Entering BIOS Setup

Before you switch your computer on again, you need to know how to enter the BIOS setup. This is usually done by pressing a particular key or a combination of keys when your computer first powers up and displays the BIOS screen. In most cases a message is displayed “Press so-and-so key to enter setup” or something similar. Some computers require you to hold a specific key while powering up the computer, or may even require that you boot the computer with a special setup disk (older computers). Consult your computer’s documentation. Some computers even automatically recognize hard drives by type and you don’t even have a say in the matter.

Here’s a list of typical BIOS setup keys:
(Thanks to Bobo for providing me with this comprehensive list)

BIOS stands for Basic Input Output System. It is a small program that is stored permanently on a chip on your motherboard. This program is the first thing that runs every time you turn your PC on. It performs a check on all the essential hardware connected to your system, such as the memory and CPU, and detects if there are any devices connected to the IDE controllers such as – you guessed it – your hard drive, and tries to identify them. By entering the BIOS you get the option to modify certain values. In this case, you can tell the BIOS to autodetect the drive and recognize automatically what type of drive it is and how big it is. But you can also type that information in manually if the BIOS cannot detect it correctly.

Entering the Parameters

Insert a DOS bootdisk from your version of Windows. A Windows 95 or 98 Startup Disk is good for this. You do have one, right? Turn your computer on and enter the BIOS by pressing the appropriate key at the appropriate time. Now, most BIOS setup utilities will have a main menu. What we are interested in here is Standard CMOS Setup or perhaps Autodetect IDE Hard Drives or Fixed Disks perhaps. It depends on your computer’s BIOS. Go to the area where hard disks are defined, and under Primary master, select Auto or enter a drive type or parameters from the label on the drive or the documentation. Depending on the age of your computer, it may not have an Auto setting and may not have a drive type number that corresponds to your type of drive. In that case, choose User Defined and enter the correct parameters. But I recommend trying Auto first as it most likely will work with any halfway new PC and make this part of the job very easy.

Here is where this gets tricky, if you have an older BIOS (e.g. a 486 computer) and just bought a brand new large hard drive, your BIOS may not be able to accommodate that drive. That does not mean you cannot use it, but it does mean that you won’t be able to utilize the full capacity. Alternatively, most manufacturers of large hard drives have a utility that you can use to set up the hard drive and it will install a driver overlay to get around the BIOS limitation. An example of this is EZDrive with EZBios from Western Digital. Consult the Hard Disk vendor’s web site to find such a utility.

If you have autodetect and it correctly identifies your hard drive and reports the correct type and mode (e.g. UDMA mode 2 or PIO 4) you’re all set. If not, go through the predefined types and choose one that best matches your drive. If you must enter parameters yourself, choose User Defined and enter the Cylinders, Heads and Sectors and choose LBA mode (Logical Block Addressing). If you do not have LBA mode, you will only be able to use 528 Mb of your hard drive and you must seek a drive setup utility with a driver overlay. Pentium computers and newer usually have LBA mode but still may not correctly support the size of hard drive you have. Again, seek a solution from the vendor’s Web site. Alternatively, consult the manufacturer of your computer or motherboard to see if a bios upgrade is available.

If your computer does not offer an exact match for the drive type number, and doesn’t have a User Defined setting for you to enter parameters, you can improvise by choosing the correct number of heads but selecting a smaller number of cylinders than the drive actually has. Choose the number of cylinders closest to the number that your drive has, but do not go over. Using fewer cylinders will result in reduced disk capacity though, as the rest will be unused.

Once you have the correct parameters entered, or auto selected or used the function to Autodetect and the drive type is correctly identified, save the CMOS settings and exit. Your computer will restart and because you have a DOS boot disk in the drive the computer will boot from it. If you cannot boot from a boot disk, then go back into your CMOS setup and set the boot sequence such that Floppy or Drive A is first. You are now ready to prepare the hard drive for use. In other words, you must partition and format it. If you need instructions on how to do that, please refer to our tutorial on How To Clean Install Windows. It includes instructions how to partition and format. Once you’re sure that everything is going to be OK, shut the computer off and replace the cover. The rest of what you have to do is with software.

That pretty much covers how to replace an IDE hard drive, but what if your present hard drive is still good and you want to use it? The next part of the tutorial covers how to set up the new drive in a Master/Slave relationship.